Fluxing composition



Patented Mar. 16, 1943 PATENT Lori-"res v lfbvxn zxosrrron I w v r. m. was a" C flomnanv, New Yo k.

ls i st ii s r Ne Application-November f8, 1941,

s s me. 419,059

s (oi. res-25) ne present nvention relates-ta 5,-801dering fluxfor use. in soldering metallic parts such as the side seams in cam bodies and has particular reference to a resin petroleum naphtha flux which. possesses i improved l characteristics. overconventiolial M 111, X- 41 W3 1i P 101.

- ace tre es ls srsi ed qnd-wh a for soldering can bodies.

The present inventipn'conteniplatesJhe a special petroleum naphtha known asfltoddard solvent for the solvent phase andrnsin as the activeiluxing agent. Stoddard solvent is known petroleum. distillate largely used inhthe,

dry cleaning industryfl d th United stst scs,

emmenthas established certain standards definition for this material. Referenceis madeto a United States Department, of. Commerce mize the fire hazard during the commercial use of the nux and second to avoid waste of the fluxmg material by evaporation of the solvent. Furthermore, the wetting properties of this alcohol resin flux leaves much to be desired.

A naphtha rosin i'iux embodying the present invention, on the other hand, possesses superior qualities as to the various features mentioned. The naphtha is more economical in its initial cost as compared to alcohol. It is more economical to use as less solder is required because of better distribution within a ziven joint. The naphtha having a-relatively high boiling point and flash point as compared to alcohol, is a less fire hasard and it does not evaporate from the flux pot while it [is being applied. This avoids waste of the iiuxing material.

.Thespecial rosin'flu'x of the present invention possesses greatly improved carrier wetting properties and this results in a considerable saving of solder. Actual commercial tests which have been run in the soldering of millions of cans to S-tQd r snasolder flow and improved adhesion'of-the solder" manufacture rs ='and; therefore, no-oiletastesare imparted-by rea'-= conditions showthat the soldered joint" made with the naphtha rosin flux is from two to four-times stronger. It is believed that this is due in large part to the improved wetting properties imparted to the flux bythenaphtha resulting in {a better in the :ioint'.

An object of the invention is the provision of an improved rosin flux for-use in soldering 'm'etal lie-surfaces wherein the'pet'roleum naphtha sel vent known as Stoddard solvent is'combined with rosin in such .a manner as to produce a'solderirig flux possessing greatly improved characteristics; Another objectistheiprovision of an improved soldering flux wherein the solvent phase has 'a'" i relativelyhigh flash point, thus eliminating fire hazards but also permitting its complete eva'p oration during the regular solderingoperation that-"theresis no danger of" contamination-of the food contents in cans containing such-productson of flu; contaminatiom a:

lfet another; object is:the provision'df such-=a' flux which when .used' for; selderingseams in:-

metallic cans such as are made from tin coated plate, or from uncoated steel plate provides a soldered Joint in which the solder is more uniform inappearance, has better distribution'and a finer grain structure with attendant improved adhesion which it would appear is the result of greater solvent wetting action on the plate.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description'which is of a preferred embodiment thereof.

* e The Stoddard solvent used in providing the ldering flux of the present invention has an initial boiling point in the neighborhood of 300 1. and an end point oi. 420 F. In other words actual tests have shown that not more than 5 percent of the petroleum naphtha distiils over below 300 F. and not less than 95 percent distills over at or blow 420 1 This means that higher soldering temperatures can be used in soldering cans with the improved flux and a better wiping action is made available to the can-manushow a definite saving of solder as compared with cans using the conventional alcohol rosin flux scale soldering of cans.

facture by such a use.

The relatively high initial boiling point which means slower evaporation while in the flux pot, maintains the fluxing material in morev workable form over extended time intervals and accordingly improves theoommereial operation of large The resin used in making the flux of the present invention may be of the usual quality as used in making the conventional alcohol rosin flux. The rosin is a natural resin although some rosin derivatives may function equally well. The size of the rosin lumps is immaterial, the actual cutting of the rosin in the naphtha being carried out in any suitable manner to insure that the rosin is completely dissolved. Obviously a pow-..

dered rosin will require less time to dissolvethan where lumps are present, but in making the flux preparation it is not necessary nor is it desirable to grind or powder the rosin.

Substantially seven pounds of the conventional grade of rosin are completely soluble in one gale ion of the Stoddard solvent. However, such a large rosin content is too concentrated for fliux purposes in can soldering and is not used. A range of rosin amounts for flux uses is from V pound to five pounds of rosin cut in one gallon of the naphtha.

While the exact manner of cutting the rosin in the naphtha is not critical, the following ex ample is given for preparing a rosin naphtha flux suitable for use in soldering side seams of metallic can bodies. It will be understood that this is but one method of procedure and any other manner of preparing the flux which insures solution of the rosi'n is satisfactory and is with-- in the scope of the present invention.

,A large metal tank is used for the mixing of the materials. Such a'tank preferably is fitted with a spigot located in the tank wall about two inches from the bottom. The desired quantity of rosin is weighed and put in the tank. This rosin may be in lump form, as previously suggested, it

being customary to use the rosin as it is received.

The proper volume of Stoddard solvent is then added. A conventional formula largely used is one pound of rosin for each gallon of naphtha. Occasional stirring with a wooden paddle is necessary. to produce the best results. A short stirring period every two hours is satisfactory. With such a stirring procedure the total dissolving time will require approximately 24 hours.- This are soldered by use of such a flux have stronger seams of improved appearance.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the -tter of the ingredients, their identity and their proportions without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbeiore described being merely a preferred embodiment thereof.

I claim:

1. A liquid rosin flux composition for soldering the seams of can bodies and the like, having improved wetting and solder disseminating characteristics, comprising a resinous material dissolved in a petroleum naphtha solvent as a carrying vehicle.

2. A liquid rosin flux compositionior soldering the seams of can bodies and the like, having improved wetting and solder disseminating characteristics, comprising a rosin dissolved in a Stoddard solvent as a carrying vehicle.

3. A liquid rosin flux composition for soldering the seams of can bodies and the like, having improved wetting and solder disseminating characteristics, comprising a solution of rosin and Stoddard solvent as a carrying vehicle in the proportlons of from V to 5 pounds of rosin for each gallon of the solvent.

FRANCIS J. DASHNER. 

